Couch to 5K
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Running with an underactive thyroid or, Die! gland. Die!

I like running. My mental health likes running, to the extent that my dose of lithium was decreased slightly. My thyroid most definitely does not. Since I started, just over three months ago, I have found it hard to lose weight I'd started to gain again (and I have to be more careful than most as diabetes is just a bowl of cocoa pops away) and my bloodwork numbers have both plummeted and risen five fold, depending on which test you're looking at; I've had an underactive thyroid for nearly 20 years now.

Bit of a bugger, really. Last night I went out for a run and in acknowledgement of the fact that I was dog tired I decided on a slow 20-minute run. Couldn't even go for five minutes at my normal pace. Felt really pissed off. Went with five-minute running intervals, interspersed with three minutes of walking.

I now have lovely muscly knees but my inner thighs are like bloody marshmallows; my trousers are slowly turning into 'jeggings' (oh, how I hate that word).

Watching my calorie intake like a hawk, keeping it to about 1200kcal / day (including eating back exercise calories) to mitigate against the hypothyroid-induced weight gain.

Rant rant rant, moan moan moan. Feel my pain, people! :)

3 Replies

I feel your pain and understand it. I only have half a thyroid after radiation treatment. Two things that I found with running and my thyroid. Mine I have to keep an eye on my ferritin levels as they give very similar symptoms to under active thyroid for me and also I have had to have a slight increase in dose (25mg every other day.) since starting to run. Mine we think was due to a healthier diet and increasing my fibre intake. We have such sensitive bodies. I hope you have a good doctor that you can ask for a couple tests. I don't know your height or anything but my body holds onto its weight if I go under 1500 calories a day I can only lose 1lb a week and even that is hard. My body is actually at its happiest at 1800 and exercise of 300. But it would be impossible for me to lose any weight at 1200 my body would hold on to everything as it would feel like it was being starved. I need the energy to run. Good luck in your journey.


At 5'1" I would normally be taking in 1500kcal, but I'd started to gain weight even before I started running as my fT4 number started gently going down (I like to keep it around 19 or so). I wouldn't ever go under 1200kcal, but I had successfully lost three stones and kept it all stable for about a year at 1500kcal. If I eat more than 1200kcal now I will balloon, there's no doubt about that. I was 7st 12lb before this all kicked off and finding it very easy to maintain; now I'm about half a stone heavier and really f'd off about it all. Off to France for a holiday next week and will get my bloods for ferritin, vitamin b12 and folate done privately there as it's much less of a hassle than getting them done privately in the UK. I do know that my ferritin needs to be over 70 in order to aid absorption, and vit b12 and folate at the upper end of the range to aid conversion of T4 to the more active T3.


I know very little about thyroid problems or ferritin levels but I do feel for you. Running can have a such a positive impact in all sorts of ways so I hope you get things sorted out soon.


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